Articles and structures prepared by three-dimensional printing method

ABSTRACT

The present invention relates to articles prepared using a three-dimensional printing method, an auxiliary structure being additionally formed beyond an extension of the one or more components during the construction of components. The invention also relates to an auxiliary structure for components produced by means of three-dimensional printing methods, the auxiliary structure being constructed along with the component and extending beyond a dimension of the one or more components.

CLAIM OF PRIORITY

The present invention is a continuation of U.S. patent application Ser.No. 15/345,589 filed Nov. 8, 2016, which is a divisional patentapplication of U.S. patent application Ser. No. 12/669,063 having a371(c) date of May 16, 2011, which claims priority from German PatentApplication No. DE 102007033434, filed on Jul. 18, 2007 and is theNational Phase of PCT Patent Application PCT/DE2008/001073, filed onJul. 1, 2008. The disclosure of U.S. patent application Ser. Nos.15/345,589 and 12/669,063, German Patent Application DE 102007033434,and PCT Patent Application PCT/DE2008/001073 are each incorporatedherein by reference in its entirety.

FIELD

The present invention relates to a method for producingthree-dimensional components, using a three-dimensional printing method.

BACKGROUND

Methods for producing three-dimensional components have been known forsome time.

For example, a method for producing three-dimensional objects fromcomputer data is described in the European patent specification EP 0 431924 B1. In this method, a particulate material is deposited in a thinlayer onto a platform, and a binder material is selectively printed onthe particulate material, using a print head. The particle area ontowhich the binder is printed sticks together and solidifies under theinfluence of the binder and, if necessary, an additional hardener. Theplatform is then lowered by a distance of one layer thickness into abuild cylinder and provided with a new layer of particulate material,which is also printed as described above. These steps are repeated untila certain, desired height of the object is achieved. A three-dimensionalobject is thereby produced from the printed and solidified areas.

After it is completed, this object produced from solidified particulatematerial is embedded in loose particulate material and is subsequentlyremoved therefrom. This is done, for example, using an extractor. Thisleaves the desired objects, from which the remaining power is removed,for example by brushing.

Other powder-supported rapid prototyping processes work in a similarmanner, for example selective laser sintering or electron beamsintering, in which a loose particulate material is also deposited inlayers and selectively solidified with the aid of a controlled physicalradiation source.

All these methods are referred to collectively below as“three-dimensional printing method” or “3D printing method”.

In all of these three-dimensional printing methods, the loose,unsolidified particulate material supports the structural body duringand after construction of the structural body. However, additionalsupport structures, which are necessary, for example, in a differentlayering method (the so-called stereolithographic method), are usuallynot required in the 3D printing method.

This characteristic has so far been regarded as a great advantage of the3D printing method, since manual post-processing of the components isnot required in order to remove any support structures.

However, if a method such as powder-supported rapid prototyping is usedin order to produce a larger number of objects, a variety of problemsmay potentially arise.

After they are completed, the parts are entirely covered by looseparticulate material and are therefore initially not visible to theoperator. If the operator uses an extractor to remove the looseparticulate material, the produced objects are in danger of beingdamaged by the suction nozzle. In the case of small parts, inparticular, the parts are also in danger of being unintentionally drawninto the suction nozzle.

Large, filigree structures may also be damaged after production whenthey are removed from the powder bed, if parts of the object are stilllocated in the powder bed and are somewhat more difficult to remove.

It is also possible for components to become dislodged and slip orcollapse under their own weight if the loose particulate materialbeneath the component is carelessly removed.

For all of these reasons, it has not yet been possible to automate theremoval of the components from the powder bed.

SUMMARY

An object of the present invention is therefore to provide a method anda device which make it possible to easily and safely remove any3D-printed object from the loose particulate material.

According to the invention, this object is achieved by a method forproducing three-dimensional components using a three-dimensionalprinting method, an auxiliary structure additionally being formed beyondthe extension of the one or more components during the construction ofcomponents.

The object is also achieved by an auxiliary structure according to theinvention for components produced by means of three-dimensional printingmethods, the auxiliary structure being constructed along with thecomponent and extending beyond a dimension of the one or morecomponents.

By additionally constructing an auxiliary structure of this type, it isa great deal easier to handle potentially small and filigree-structuredcomponents.

According to a preferred embodiment of the method according to theinvention, the auxiliary structure is additionally constructed in such away that two simultaneously constructed components are interconnecteddirectly or indirectly by the auxiliary structure.

In such an embodiment of the present invention, it potentially becomeeven easier to handle the produced components, since multiple componentsmay be removed at the same time. This may be advantageous, inparticular, if the components are relatively small.

In a method according to the invention, the auxiliary structure mayadvantageously include materials of the component.

Such an embodiment of the method according to the invention makes iteasy to construct the auxiliary structure and also requires only areasonable amount of additional time to construct the auxiliarystructure.

According to a particularly preferred embodiment of the present method,the auxiliary structure is largely formed from the same material as theone or more components. This potentially makes it particularly easy toadditionally build the auxiliary structure.

According to a particularly preferred embodiment of the method accordingto the invention, multiple layers of components are formed on top ofeach other. This means that, during a single build process, multiplecomponents may be formed not only next to each other, but also on top ofeach other. In the event that particularly small or even onlyparticularly flat components are to be constructed, this is a possibleembodiment of the method.

The auxiliary structure may have any conceivable shape. However, it maybe advantageous if, in the event that multiple components are producedon top of each other, a separate auxiliary structure containing allcomponents on a layer is formed on each layer of components.

In the method, as described according to the invention, it is possibleaccording to an embodiment of the present invention to form thecomponent and the auxiliary structure with the aid of particulatematerials deposited in layers and by adding a further material or byselectively applying energy.

According to the method, the auxiliary structure is preferably formed insuch a way that it is connected to at least one component. It istherefore also conceivable that in some embodiments it is advantageousto interconnect all components of a manufacturing process.

It may also be advantageous to form predetermined break points atjunctions between the component and auxiliary structure in the methodaccording to the invention.

According to an embodiment of the invention, it has also proven to behelpful if the auxiliary structure further forms a holder or couplingdevice, since this makes it particularly easy to handle the formedcomponents. A holding device of this type may be a holder for a handlingtool.

A further improvement achievable by an auxiliary structure according tothe present invention is that the auxiliary structure may enable thehandling of components to be automated.

To make the components particularly easy to handle, the auxiliarystructure, according to one embodiment, connects at least two componenton a component layer.

It may also prove to be particularly advantageous if the auxiliarystructure interconnects all constructed components. This makes itparticularly easy to remove the components after they have beencompleted, and this may be done in a single operation.

According to an embodiment of the invention, it may be useful to alwaysorient the auxiliary structure on one side of the build cylinder inorder to have a uniform starting point for any removal devices and thento group the desired components on this side, which saves space. Due toknown build time considerations, it would then be possible for the restof the auxiliary structure to follow the contours of the components asclosely as possible.

It would be possible to connect the auxiliary structure directly to theone or more components.

A further possibility would be to connect the auxiliary structureindirectly to the one or more components, for the auxiliary structuredoes not necessary have to be integrally connected to the component.Embodiments are also conceivable in which the auxiliary structure holdsthe component in a positive fit or is even positioned a short distanceaway from the component, permitting slight movements of the component.

It may also be possible to design the auxiliary structure as a kind oflattice box surrounding the component, which has only thin strips forseparating the space segments.

According to a particularly preferred embodiment of the presentinvention, the determination of the suitable auxiliary structure shouldbe automated as much as possible in process-preparing software.

For example, a possible workflow would be to place the parts to be builtin the virtual build space, using a computing program. In a subsequentstep, the operator marks the positions on the components for connectingthe auxiliary structure. The process software subsequently computes theoptimized auxiliary structure and also dimensions it on the basis of theavailable data relating to component volume and therefore weight.

Next, the entire build space, including the auxiliary structure, isdivided into the desired layers, and this data is then transferred tothe layering process, which enables the component and the auxiliarystructure to be constructed by means of the desired 3D printing method.

The auxiliary structure may also be used to facilitate componentidentification, for example by applying component numbers or componentcodes to the strips for the corresponding components. These codes may beprovided, for example, in machine-readable form so that they may besupplied to an automated evaluation system.

According to a further embodiment of the invention, a method forproducing three-dimensional components from a particulate base materialis provided. The base material is deposited in layers and subsequentlyconnected selectively along a contour of the component predetermined bya controller by adding a further material or applying energy. Thecomponent is completed by repeating this operation multiple times. Inthe present case, an auxiliary structure is preferably constructed alongwith the component, and this auxiliary structure holds the one or morecomponents to be constructed in the desired position within the buildspace even without the supporting effect of the surrounding powdermaterial.

If, according to a particularly preferred embodiment of the presentinvention, the auxiliary structure has a different color than thecomponent, it may be, for one thing, particularly easy to handle thecomponents, since it is very easy even for a machine to determine whatthe auxiliary structure represents and where it should be possible togrip the formed structure.

For the purpose of more detailed explanation, the invention is describedin further detail below on the basis of preferred embodiments withreference to the drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an auxiliary structure designed as a frame according to afirst preferred embodiment of the present invention.

FIG. 2 shows a possible shape of an auxiliary structure for connectionto the components, according to a further embodiment of the presentinvention.

FIG. 3 shows a system of multiple components in a build cylinderaccording to a third preferred embodiment of the method according to theinvention.

FIG. 4 shows an automated means of removing components provided withauxiliary structures.

DETAILED DESCRIPTION

FIG. 1 shows a top view of a connection of multiple components 1 havingan auxiliary structure 2, auxiliary structure 2 including a frame 4surrounding components 1. Components 1 are connected to frame 4 bystrips 3.

According to the embodiment of the invention illustrated in FIG. 1,auxiliary structure 2 includes frame 4, which surrounds components 1 ona plane and is connected to the individual components by strips 3. Frame4 is dimensioned in such a way that all components 1 connected theretoare held on this frame 4 by the force of their own weight withoutdamaging the frame.

To limit the amount of powder consumed, it is possible to provide atleast part of auxiliary structure 2 with a non-solid design. Forexample, it would be possible to produce at least part of frame 4 fromhollow or open profiles whose interiors may be accessible to cleaningagents via corresponding openings.

For example, frame 4 may have a rectangular cross section; however othercross sections, such as round or oval ones, are also conceivable withoutfurther limitation.

To shorten the build time for auxiliary structure 2, it may beadvantageous, according to a preferred embodiment of the invention, toposition auxiliary structure 2 as closely as possible to components 1and thereby give it a minimal dimension.

FIG. 2 shows a possible means of connecting an auxiliary structure 2 toa component 1 according to a further embodiment of the presentinvention.

To limit post-processing work for removing strips 3 or the contactpoints of strips 3 on component 1, it may be advantageous to provideauxiliary structure 2 with a minimal number of connecting points 10 tocomponents 1.

Strips 3, along with their connecting points 10, may be designed withso-called predetermined break points 9 to facilitate removal, thesepredetermined break points being provided with a geometrically definedconstriction 9, as illustrated by way of example in FIG. 2.

Alternatively or in addition, it would also be possible to producepredetermined break point 9 by reducing the solidity, for example byreducing the binder deposit.

Connecting points 10 are also preferably located at points on components1 which do not require an exact surface. It is thus undesirable for apoorly placed connecting point to mar the visual appearance.

Preferred locations for connecting points 10 may be, for example, on therear or inside surfaces of component 1. However, when selectingconnecting points 10, it is also important to ensure that accessibilityis maintained and that the connections may be removed without residue.For this reason, outwardly curved surfaces are potentially moresuitable, since they are more easily accessible than inwardly curvedsurfaces.

The number of connecting points 10 should preferably also be selected insuch a way that they are sufficient to hold connected component 1 in anyposition by the force of its own weight and, if possible, also under theinfluence of weaker or stronger additional forces followingpost-processing work.

FIG. 3 shows a system of multiple components 1 in a build cylinder 4after components 1 have been constructed, according to a furtherpreferred embodiment of the method according to the invention.

In 3D printing as well as in other RP methods, it is possible to producecomponents in multiple layers on top of each other, depending on thecomponent size and component shape. Access to the individual layers isusually only from one side, ordinarily from the side on which theparticulate material is introduced.

In order to reach the underlying components, the top components mustfirst be removed.

As shown in FIG. 3, it may therefore be advantageous to dividecomponents 1 and associated auxiliary structures 2 into different planeswhich, if necessary, run parallel to the layering plane. This enablesthe individual “component planes” to be removed easily and successively.

Auxiliary structures 2 of the individual planes should preferably beeasily separated from each other and nevertheless be fixable in placewithout supporting powder material.

Depending on the component size and component weight, it would also beconceivable to interconnect the components on different component planesvia the auxiliary structure.

It may also be advantageous if the auxiliary structure interconnects thecomponent additionally or exclusively in a direction perpendicular tothe layering direction, instead of in a direction parallel to thelayering direction.

Connecting the components to an auxiliary structure makes it possible touse automated removal and cleaning methods. This is currently madedifficult by the fact that the components are usually designedindividually and have no holding means, for example for robot grippers.The use of simple gripping mechanisms would quickly cause damage to thecomponents.

FIG. 4 shows an automated means of removing components 1 provided withauxiliary structures 2, which is made possible through the use of theauxiliary structures.

By using auxiliary structure 2, it is possible, according to anembodiment of the present invention, to define a uniform holding meansfor automatic removal or cleaning or post-processing.

A robot 7 would be able to successively remove an auxiliary structure 2provided with a frame and including components 1 and to supply them to apost-processing process such as cleaning.

Loose particle material 6 may also be more easily removed, for exampleby removing at least a portion of base 5 of the vessel where thelayering process took place, or if the base has closable openings whichare opened at the end of the process, and if the loose particulatematerial, which has a sufficient fluidity, flows out through the baseopenings.

According to this technique, components 1 are held in the predeterminedposition by auxiliary structure 2 and are not carried along byoutflowing particulate material 6.

However, it would also be possible to remove loose particulate material6 via the upper opening in the build container, for example by tiltingthe entire build container in order to pour out loose particulatematerial 6. If auxiliary structure 2 is held in place on the buildcylinder, for example by clamps, components 1, including auxiliarystructure 2, remain in the predefined position is not impaired by thisoperation and are therefore also not damaged.

It would also be possible to extract loose particulate material 6, as isknown from the prior art. A suction lance may be positioned over thepowder feedstock from above, or the suction lance is inserted directlyinto the powder feedstock, and the loose particulate material then flowsto the suction nozzle. In both cases, components 1 remain in a desiredposition due to auxiliary structure 2, and they are therefore notunintentionally extracted or damaged.

After a large part of loose particulate material 6 has been removed,components 1, including auxiliary structure 2, may be removed from thebuild container and supplied to a further cleaning process. This may bedone using compressed air or compressed air combined with blastingmedia. In this case, auxiliary structure 2 again enables components 1 toremain in a desired position and the cleaning agents to be passed overcomponents 1. This operation may be carried out manually orautomatically. For example, it would be conceivable to use an automaticcleaning system into which multiple standardized auxiliary structureframes 4, including components 1, are introduced, and by means of whichcomponents 1 may be cleaned of remaining residual particulate material 6in a closed process chamber, using a fluid medium such as compressedair.

Particulate material 6 separated from component 1 may then be suppliedto a separator via a process chamber extraction system and fed back intothe build process.

The strong flow rates needed in an automatic cleaning system of thistype require components 1 to be sufficiently fixed in place, which maybe accomplished with the aid of auxiliary structure 2.

After cleaning, components 1 may have to be infiltrated in order toachieve certain material properties. This may be accomplished byimmersing the components into a tank filled with fluid infiltrationmedium 8.

This operation may be greatly facilitated by auxiliary structure 2,since multiple components 1 may be easily held at once and thus alsosafely immersed at once. In this case, it is also possible to easilyautomate the operation by introducing one or more frames, for exampleinto a lattice box, and then immersing them together with the latticebox into infiltration tank 8, as shown, for example, in FIG. 4. Ofcourse, it is also conceivable to automate the immersion of individual“component layers”.

Finally, components 1 must be separated from auxiliary structure 2.

It is helpful to distinguish the auxiliary structure from the componentwith the aid of colors, which may be accomplished, for example, byapplying additional dye during the 3D printing process or by means of amodified chemical reaction via overhardening or underhardening. Adistinction may also conceivably be made by means of a particularsurface structure which is used only in the auxiliary structure.

What is claimed is:
 1. An article comprising an auxiliary structure; and one or more components produced by means of a three-dimensional printing method, whereby the auxiliary structure is constructed along with the one or more components and extending beyond a dimension of the one or more components; wherein the auxiliary structure is connected directly to the one or more components; and the auxiliary structure and the one or more components are formed from a same material; wherein the same material includes a binder material.
 2. The article of claim 1, wherein the auxiliary structure forms a holder or a coupling device for handling the component(s) after removing the auxiliary structure and the component(s) from a surrounding material.
 3. The article of claim 1, wherein the auxiliary structure enables an automated handling of the components after removing the auxiliary structure and the component(s) from a surrounding material.
 4. The article of claim 1, wherein all constructed components are connected to the auxiliary structure.
 5. The article of claim 1, wherein the one or more components includes a first component and a second component and the auxiliary structure is connected directly to the first and second components.
 6. The article of claim 1, wherein the auxiliary structure largely surrounds one or more of the components.
 7. The article of claim 1, wherein the article includes a predetermined break points formed at junctions between each of the components and the auxiliary structure.
 8. The article of claim 1, wherein the auxiliary structure is connected to a first component at a first predetermined break point, wherein the first predetermined break point has a reduced amount of the binder.
 9. An article comprising an auxiliary structure; and multiple components produced by means of a three-dimensional printing method, whereby the auxiliary structure is constructed along with the components and extending beyond a dimension of the components; wherein the auxiliary structure and the components are formed from a same material; wherein the auxiliary structure is directly connected to two or more of the multiple components; and the article includes multiple layers of components.
 10. The article of claim 9, wherein the auxiliary structure and the multiple components include a material deposited in layers and connected selectively by a further material or by applying energy; and the multiple components have a structure capable of being infiltrated by a fluid infiltration medium.
 11. The article of claim 10, wherein the auxiliary structure or a different auxiliary structure is directly connected to each of the multiple components.
 12. The article of claim 9, wherein the article includes a separate auxiliary structure on each layer of components.
 13. An article comprising an auxiliary structure; and multiple components produced by means of a three-dimensional printing method, whereby the auxiliary structure is constructed along with the components and extending beyond a dimension of the one or more components; wherein the auxiliary structure is connected directly to one or more of the multiple components; and the auxiliary structure and the multiple components are formed from a same material; wherein the article includes a loose material between two of the two or more of the multiple components and/or between adjacent layers of the multiple components.
 14. The article of claim 13, wherein the multiple components includes a first component and a second component, the auxiliary structure and the first and second components include the same material deposited in layers and connected selectively by a further material or by applying energy; and the first and second components have a structure capable of being infiltrated by a fluid infiltration medium.
 15. The article of claim 14, wherein the auxiliary structure is connected to the first component at a first predetermined break point and is connected to the second component at a second predetermined break point. 